Study Of Energy Saving Method Of A Hybrid VAV Air Conditioning System Based On Particle Swarm Optimization Algorithm

As we all known,air conditioning occupies a largely of energy consumption in the buildings,improve its energy-saving performance is great significance to reduce building energy consumption.At present,the comfortable air condition mostly adopts the maximum temperature difference air supply method.Low temperature will cause condensation on the surface of supply air outlet,and too small air volume will worsen the indoor air quality.Unfortunately,increase outlet air temperature will makes the conventional air conditioner electrical heating power consumption increases,its coefficient of performance decreases.The multi-condenser system that could recycle sensible heat of exhaust air and recovery some condensing heat release due to indoor air temperature and humidity is low in hot humidity climate.The driving force of water evaporation cooling is enthalpy difference.With indirect evaporative cooler as the exhaust air energy recovery device,not only can recovery its total heat energy,and won’t add to the air moisture content at primary.Integrated the advantages of these two systems,this paper proposes a hybrid air conditioning system that combined two-stage indirect evaporative cooling and vapor compression refrigeration cycle,to improve indoor thermal comfortable environment and the energy-saving efficiency of the air conditioner.In order to study the hybrid air conditioning system energy saving potential,this paper made the following several aspects work: First,set up a mathematical model of hybrid air conditioner contains two-stage indirect evaporative cooling system and the dual-condenser system.Second,the influences of supply air temperature difference on the optimal ratio of evaporator and reheat condenser of dual-condenser system was analyzed,and the coefficients of performance(COP)of both the dual-condenser system and the conventional air conditioning was calculated under the hot humidity climate.Three,analysis of the relationship between the refrigerating capacity and the structure parameters of dew-point evaporative cooler,and compared the three kinds of indirect evaporative cooling system of exhaust air energy recovery ability.Four,a binary regression relationship was established between the number of the working condition clusters and relative error in air-conditioning energy consumption by using the new peak density clustering algorithm(DPC),and a kind of simplified load clustering algorithm in energy consumption calculation was obtained.Finally,the life cycle cost(LCC)of hybrid air conditioner in the office room in changsha city was optimized by using particle swarm optimization algorithm.Through the calculation of annual energy consumption for the room,the amount of hybrid air conditioner is 3566.7 k W,more than the conventional air conditioner and dual-condenser air conditioner saves 1794.6 k W and 672.2 k W respectively.The target system to increase the investment cost of 1202.6 yuan,its minimum LCC is 24413.68 yuan,recovery period is 2.98 years.With the decrease of the supply air temperature difference,the saving-energy efficiency of the hybrid air conditioning increased.Compared with the conventional air conditioner,the annual saving-energy efficiency of hybrid air conditioner from 55.93 % to 16.76 %,higher than that of dual-condenser air conditioner from 51.37 % to 2.49 % within the supply air temperature difference from 3 ℃ to 9 ℃.